<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Vue中的列表过渡</title>
    <script src="../vue.js"></script> 
   
    <style>
      .v-enter, .v-leave-to {
          opacity: 0;
      }
      .v-enter-active, .v-leave-active {
          transition: opacity 1s；
      }
    </style>
</head>
<body>
    <div id="root"> 
        <transition-group>
             <!--   尽量不要用索引 index 作为 key值 -->
            <div v-for="item of list" :key="item.id">
                {{item.title}}
            </div>
        </transition-group>
       
        <button @click="handleBtnClick">Add</button>
    </div>   
    
    <script>      
    
        var count = 0;
        var root = new Vue({
            el: '#root',
            data: {
               list: []
            },            
            methods: {
                handleBtnClick: function(){
                    this.list.push({
                        id: count++,
                        title: 'hello world'
                    });
                }
            }        
           
        });
    </script>
</body>
</html>